Five Rapper-Rocker Collaborations Before Big Boi and Modest Mouse

Outkast's Big Boi and Andre 3000 haven't parted ways, but, as evidenced by Big Boi's solo album and their complete separation from each other on their own CDs, they don't want to spend too much time together. Plus, as Big Boi revealed on his Twitter, he has started seeing other people. He's rocking out with Modest Mouse. (And just in case you were hoping for some sick Daddy Fat Sax flow over "Float On," Lupe Fiasco already mucked that plan with "The Show Goes On.")

We're sure Outkast'll be fine. While we wonder what this team-up is going to sound like, let's remember and watch some classic hip-hop and rock collaborations.

Sonic Youth and Cypress Hill

Off the Judgment Night soundtrack, this smooth groovy jam is a lot more Cypress Hill than it is Sonic Youth. Sounds like it was recorded in Cheech and Chong's tour van from Up in Smoke. This is the good shit, holmes.

R.E.M. and KRS-One

Sometimes we forget what a big deal R.E.M.'s album Out of Time was. Besides turning R.E.M. into superstars and the face of MTV for most of 1991, this tape turned a lot of 9- to 11-year-olds onto one the smartest MCs to ever grab a mic, KRS-One. There was a lot of MC Hammer and Vanilla Ice going on around that time -- thanks to this jam, lots of skater dudes had an idea of what real hip-hop was.

Public Enemy and Anthrax

Perfect. Just perfect. Thrash metal plus Chuck D, Flava Flav, and Terminator X. Listen to it loud, at work, and watch your boss get uncomfortable. 0:56-1:06 are the best ten seconds of rap-rock ever.

House of Pain and Helmet

Another one off of that Judgment Night soundtrack, the soundtrack that made rap-rock a thing. No, it's not the birth of the usually awkward and ugly son of metal and hip-hop. Yes, it is the birth of people spending tons of money on it. Fun fact: Most people who own this soundtrack haven't seen the entire movie (SPOILER ALERT: Denis Leary spends a long time screaming at Cuba Gooding Jr. and Emilio Estevez while they are trapped in a shipping container or something). This song is still tough as hell; it probably played a role in inspiring tough-guy hardcore's pit ethic.

RUN-DMC and Aerosmith

Duh. This song resurrected Aerosmith's career and fed hip-hop to the masses. You know this.